Bone growth involves the formation of hydroxyapatite, HA, nanocrystals in the body. In vitro studies showed that HA does not precipitate directly, but that amorphous calcium phosphate, ACP, is a precursor of biological HA. Stable synthetic ACP can be consistently prepared using standard methods, such as mixing solutions of ammonium phosphate and Ca chloride, and is found to have a composition of Ca3(PO4)2¿5H2O¿CO2 including structural water. We previously carried out a study of ACP after heat treatment up to 450°C to reduce the proton content. That study included neutron diffraction measured on SANDALS. A key scientific goal remains to study pristine ACP which has not been heat treated. We would like to repeat the experiment, using a new approach to obtain a fully deuterated sample of pristine ACP.